1. Field of the Invention
This invention relates generally to a system and method for providing a vehicle roll stability indicator that is indicative of the potential for vehicle roll and, more particularly, to a system and method for providing a vehicle roll stability indicator that is indicative of the potential for vehicle roll, where determining the roll stability indicator includes calculating vehicle roll energy and roll energy rate.
2. Discussion of the Related Art
It is known in the art to provide vehicle rollover control using differential braking control, rear-wheel steering control, front-wheel steering control, or any combination thereof to prevent a vehicle from rolling over. A vehicle roll prevention system may receive vehicle dynamics information from various sensors, such as yaw rate sensors, lateral acceleration sensors and roll rate sensors, to determine the proper amount of control action to be taken to prevent vehicle roll over. A balance typically needs to be provided between controlling the vehicle roll motion and the vehicle yaw motion to provide the optimal vehicle response. Thus, it is usually necessary to detect certain vehicle conditions to provide the roll prevention control.
Various methodologies are known in the art to detect these vehicle conditions. Specifically, rollover determination can be based on vehicle roll rate from a roll rate sensor and roll angle estimation. For prior techniques, thresholds for roll rate and roll angle are established to detect an imminent rollover. Even though roll rate and roll angle are the two most important elements for detecting vehicle roll motion, they do not reflect the total vehicle roll energy that would eventually determine the vehicles propensity to roll over.